请教在STM32F207ZGT6上使用USART3的初始化代码

着调

新近接触F207，求高手代码，初始化USART3.谢谢了

着调

void Printf_Init(void)
{
    USART_InitTypeDef USART_InitStructure;   
      
    SystemCoreClockUpdate();
      
    /* USARTx configured as follow:
          - BaudRate = 115200 baud  
          - Word Length = 8 Bits
          - One Stop Bit
          - No parity
          - Hardware flow control disabled (RTS and CTS signals)
          - Receive and transmit enabled
    */
    USART_InitStructure.USART_BaudRate = 115200;
    USART_InitStructure.USART_WordLength = USART_WordLength_8b;
    USART_InitStructure.USART_StopBits = USART_StopBits_1;
    USART_InitStructure.USART_Parity = USART_Parity_No;
    USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
    USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;

    GW_COMInit(ConsolePort, &USART_InitStructure);

    /* Output a message on Hyperterminal using printf function */
    printf("%s", STM32F20x_STR);
    printf("\r\n Booting...\r\n\r\n");
   
    printf(" STM32F2XX_STDPERIPH_VERSION %d.%d.%d",
            __STM32F2XX_STDPERIPH_VERSION_MAIN,
            __STM32F2XX_STDPERIPH_VERSION_SUB1,
            __STM32F2XX_STDPERIPH_VERSION_SUB2);
    printf("\n\r Inchip Flash: 1024K bytes");
   
   
    printf("\n\r System Core Clock): %dHz.\n\r", SystemCoreClock);
   
}


/**
  * @brief  Configures COM port.
  * @param  COM: Specifies the COM port to be configured.
  *   This parameter can be one of following parameters:   
  *     @arg UplinkComPort
  *     @arg ConsolePort  
  * @param  USART_InitStruct: pointer to a USART_InitTypeDef structure that
  *   contains the configuration information for the specified USART peripheral.
  * @retval None
  */
void GW_COMInit(COM_TypeDef COM, USART_InitTypeDef* USART_InitStruct)
{
  GPIO_InitTypeDef GPIO_InitStructure;

  /* Enable GPIO clock */
  RCC_AHB1PeriphClockCmd(COM_TX_PORT_CLK[COM] | COM_RX_PORT_CLK[COM], ENABLE);

  if (COM == UplinkComPort)
  {
    /* Enable UART clock */
    RCC_APB2PeriphClockCmd(COM_USART_CLK[COM], ENABLE);
  }
  else
  {
    /* Enable UART clock */
    RCC_APB1PeriphClockCmd(COM_USART_CLK[COM], ENABLE);
  }

  /* Connect PXx to USARTx_Tx*/
  GPIO_PinAFConfig(COM_TX_PORT[COM], COM_TX_PIN_SOURCE[COM], COM_TX_AF[COM]);

  /* Connect PXx to USARTx_Rx*/
  GPIO_PinAFConfig(COM_RX_PORT[COM], COM_RX_PIN_SOURCE[COM], COM_RX_AF[COM]);

  /* Configure USART Tx as alternate function  */
  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;

  GPIO_InitStructure.GPIO_Pin = COM_TX_PIN[COM];
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_Init(COM_TX_PORT[COM], &GPIO_InitStructure);

  /* Configure USART Rx as alternate function  */
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
  GPIO_InitStructure.GPIO_Pin = COM_RX_PIN[COM];
  GPIO_Init(COM_RX_PORT[COM], &GPIO_InitStructure);

  /* USART configuration */
  USART_Init(COM_USART[COM], USART_InitStruct);
   
  /* Enable USART */
  USART_Cmd(COM_USART[COM], ENABLE);
}